A known central inverter having the model designation “CP” by the applicant has an inverter comprising an inverter bridge, which is connected on the input side between two DC busbars and on the output side to an AC output line, wherein the inverter bridge has a parallel circuit comprising two semiconductor switches between the AC output line and each DC busbar. Owing to the parallel circuit of semiconductor switches, an increased current-carrying capacity is achieved in comparison with in each case only one semiconductor switch. The known inverter is therefore particularly suitable for high alternating currents output via the AC output line. In the specific design configuration, the known inverter has two semiconductor modules arranged next to one another, which each form two semiconductor switches connected in parallel. The semiconductor modules are connected to the two DC busbars and to the AC output via connections on connection sides oriented in the same spatial direction. In this case, the two DC busbars extend overlapping one another in parallel planes with respect to one another. A connection element which leads to the AC output is connected to the two semiconductor modules in a region which is not overlapped by the DC busbars. In the known inverter, not only one such inverter bridge is provided, but a plurality of identical inverter bridges are connected to rims of the same two DC busbars. In this case, the semiconductor modules are fitted with their fitting sides opposite the connection sides on a common heat sink.
In another known inverter comprising an inverter bridge, which is connected on the input side between two DC busbars and on the output side to an AC output line, the inverter bridge has a series circuit comprising two semiconductor switches between the AC output line and each DC busbar. The series circuits comprising semiconductor switches serve the purpose of allowing the voltages present across the inverter bridge and/or between the AC output and the two DC busbars to form as voltage drops across a plurality of semiconductor switches. The individual semiconductor switches can therefore have a lower dielectric strength than in the case of a half bridge which has in each case only one semiconductor switch between the AC output line and each DC busbar. Such an inverter is therefore particularly suitable for high input voltages.
DE 100 44 570 A1 discloses an inverter having a modular design. The inverter comprises a central unit and a plurality of power units. The central unit has an AC voltage output and a plug-type connector female connector. The power units each have a DC voltage input and a plug-type connector female connector and a plug-type connector male connector. A power unit can be plugged with its plug-type connector male connector into the plug-type connector female connector of the central unit. Further power units can then each be plugged with their plug-type connector male connector into the plug-type connector female connector of the previously connected power unit. Each power unit has an inverter and a controller driving said inverter.
DE 10 2005 060 354 A1 discloses a modular converter system. This system has a converter basic device and at least one converter additional device, wherein these devices can be plugged laterally with one another by means of their mains and load conductor bar and by means of a communications line and are thus connected in parallel.
WO 94/14227 A1 discloses a three-phase inverter and has an inverter bridge comprising two semiconductor modules arranged next to one another on a heat sink for each phase. Each semiconductor module comprises a semiconductor switch. Initially, two DC busbars, to which the inverter bridges are connected on the input side, extend above the heat sink. Above this, in a further plane, plate-shaped connection elements for the individual phases of the AC output of the inverter extend parallel to the DC busbars. These plate-shaped connection elements are electrically insulated with respect to the DC busbars and the DC busbars are electrically insulated with respect to one another. Connections of the upper DC busbar to the semiconductor modules extend through the lower DC busbar, and connections from the plate-shaped connection elements to the semiconductor modules extend through both DC busbars.
DE 601 19 865 T2, a translation of EP 1 195 884 B1, discloses a three-phase inverter comprising three pairs of semiconductor switches, which are arranged between two DC busbars. Output-side connection elements which are connected to a center point of each pair likewise extend between the DC busbars. Such a pairwise interposition of semiconductor switches between DC busbars is also known from JP 2007215396 A.
US 2009/0257212 A1 describes a semiconductor module comprising two semiconductor switches, which are connected in series between two input connections, and an output connection, which is connected to the center point of the switches. The input connections are arranged one above the other on one side of the housing of the semiconductor module. The output connection is provided on the opposite side of the housing.